That's kind of what a new study makes it sound like, at least. Here's how Forbes puts it:

[W]hat exactly is going on in our brains when we don't get enough shuteye?

Researchers tackled this question in a new study that suggests our brains become bundles of hyper-reactive nerve cells as the sleepless hours tick by. In a sense, our noggins overheat when we deprive them of necessary down time — bad news for those of us who work into the wee hours.

Bundles of hyper-reactive nerve cells! The explanation over at Science News is only slightly less scary: basically, our brains have stronger electrical responses after a sleepless night, implying great "excitability." That might be why being sleep deprived can sometimes set off a seizure (go take a nap!) or cause hallucinations (now, before the gnomes get you!). The only bright side: this news could aid the study of depression, since going without sleep can sometimes make depressed people feel better. For healthy people, though, this is just another reason to get enough sleep: if you don't, your brain might catch fire.